1. Field of the Invention
The present invention relates to a thrust generator which may be used as a superconducting Electro Magnetic Thruster (hereinafter referred as EMT) for ship propulsion devices, a Dynamic Positioning System for ocean platforms, an Electro-Magnetic pump for an electrically conductive fluid, such as, sea water, an MHD generator, and pumps and generators of pumping-up power systems. Conventionally, diploe, quadruple, saddle and racetrack type superconducting magnets are used for EMTs. These conventional EMTs may however, be too big and too heavy to provide enough thrust for full-scale ships and may be difficult to construct. Their magnetic field must be strong enough on 10 to 20 Teslas to obtain the efficient propulsion of EMT ships. The EMT having such a strong magnetic field may be while the size and weight of an on-board EMT propulsion device is limited by available hull space. Consequently, the size, weight, thrust force and high magnetic field of conventional EMTs has proven unsatisfactory. In view of this, there is an important technical problem to develop EMTs for practical use.
2. Description of the Prior Art
A previous application by the present inventor, PCT/JP89/01153, disclosed a light weight and compact thrust generator includes superconducting magnets. According to that previous application, the superconducting EMT generator includes a superconducting solenoid magnet and a helical or spiral thrust duct with a pair of electrodes inserted in the hollow interior of the superconducting solenoid coil magnet. The openings of the inlet and the outlet of the spiral duct are provided along the longitudinal center axis of the solenoid coil magnet. In the case of sea water as a conductive fluid flowing the thrust duct an anode, or positive electrode, is arranged continuously on the inner side wall of the duct and a cathode, or negative electrode, is opposed to the outer side wall of the duct.